Starship Asterisk*

neufer wrote: ↑Mon Sep 30, 2019 3:59 pm

Chris Peterson wrote: ↑Mon Sep 30, 2019 1:50 pm

starsurfer wrote: ↑Mon Sep 30, 2019 11:12 am
Can starlight induce photosynthesis?

In general, yes (although not enough to have any biological significance to a plant). The photosynthetic pathway is triggered whenever a photon is captured. That said, there are probably some plants that shut down a part of that pathway when light levels are low, preventing the creation of sugars. Think of it as a sort of plant analog to sleeping.

https://i.pinimg.com/736x/4b/5e/3b/4b5e3b3dc3d02b07dd344cd7d19ad68d.jpg wrote:

Photograph by Tim Laman, National Geographic

---

<<Cassiopea andromeda, the upside-down jellyfish, is named for one of Greek mythology’s treacherous queens. Cassiopeia was punished by Poseidon, who deemed that her constellation often appear upside-down in the sky. Her namesake jelly often lies on the seafloor with its mouth and arms facing the surface, which allows symbiotic algae to collect sunlight for photosynthesis and pass nutrients along to the jelly. Crabs sometimes carry these jellyfish on their backs to serve as a very effective protective shield.>>

https://en.wikipedia.org/wiki/Cassiopea wrote:
Certain species of Cassiopea have been observed to enter a sleep state, indicated by a decreased pulsation rate.

https://en.wikipedia.org/wiki/Sleep_in_non-human_animals#Invertebrates wrote:
<<Sleep as a phenomenon appears to have very old evolutionary roots. Unicellular organisms do not necessarily "sleep", although many of them have pronounced circadian rhythms. The jellyfish Cassiopea is the most primitive organism in which sleep-like states have been observed. The nematode C. elegans is another primitive organism that appears to require sleep. Here, a lethargus phase occurs in short periods preceding each moult, a fact which may indicate that sleep primitively is connected to developmental processes. Raizen et al.'s results furthermore suggest that sleep is necessary for changes in the neural system. The electrophysiological study of sleep in small invertebrates is complicated. Insects go through circadian rhythms of activity and passivity but some do not seem to have a homeostatic sleep need. Insects do not seem to exhibit REM sleep. However, fruit flies appear to sleep, and systematic disturbance of that state leads to cognitive disabilities. There are several methods of measuring cognitive functions in fruit flies. A common method is to let the flies choose whether they want to fly through a tunnel that leads to a light source, or through a dark tunnel. Normally, flies are attracted to light. But if sugar is placed in the end of the dark tunnel, and something the flies dislike is placed in the end of the light tunnel, the flies will eventually learn to fly towards darkness rather than light. Flies deprived of sleep require a longer time to learn this and also forget it more quickly. If an arthropod is experimentally kept awake longer than it is used to, then its coming rest period will be prolonged. In cockroaches that rest period is characterized by the antennae being folded down and by a decreased sensitivity to external stimuli. Sleep has been described in crayfish, too, characterized by passivity and increased thresholds for sensory stimuli as well as changes in the EEG pattern, markedly differing from the patterns found in crayfish when they are awake. In honeybees, it has been suggested they could be able to dream.>>

orin stepanek wrote: ↑Mon Sep 30, 2019 10:55 pm

Chris Peterson wrote: ↑Mon Sep 30, 2019 10:27 pm

orin stepanek wrote: ↑Mon Sep 30, 2019 10:23 pm Try that with the trees in front!

Of course, in this example, the fence post is the foreground tree and the tree is Orion.

Aww Chris I don't feel like arguing! In the beginning I said that I thought that the Orion was exaggerated! I still feel that way! You showed the trees staying the same size! Orion was larger than I ever seen It! That was the point I was making! You didn't show me the trees being oversized behind the posts!
I know you're much smarter than most of us! You don't have to prove it!

Chris Peterson wrote: ↑Mon Sep 30, 2019 10:27 pm

orin stepanek wrote: ↑Mon Sep 30, 2019 10:23 pm

Chris Peterson wrote: ↑Mon Sep 30, 2019 10:00 pm

Not sure what you mean. The relative sizes have nothing to do with cropping. They depend only on the distance between the camera and the foreground (terrestrial) objects or landscape.

Which of these is more "real"? (The background tree is the same size in both.)
_
Scale2.jpg

Try that with the trees in front!

Of course, in this example, the fence post is the foreground tree and the tree is Orion.

orin stepanek wrote: ↑Mon Sep 30, 2019 10:23 pm

Chris Peterson wrote: ↑Mon Sep 30, 2019 10:00 pm

orin stepanek wrote: ↑Mon Sep 30, 2019 9:58 pm

I do a lot of cropping to fit screen size for my desktop screen and have never run into that! So Whatever!

Not sure what you mean. The relative sizes have nothing to do with cropping. They depend only on the distance between the camera and the foreground (terrestrial) objects or landscape.

Which of these is more "real"? (The background tree is the same size in both.)
_
Scale2.jpg

Try that with the trees in front!

Chris Peterson wrote: ↑Mon Sep 30, 2019 10:00 pm

orin stepanek wrote: ↑Mon Sep 30, 2019 9:58 pm

Chris Peterson wrote: ↑Mon Sep 30, 2019 9:33 pm
What is a "normal sized tree"? The only thing that determines the relative sizes of the tree and Orion is the distance of the camera from the tree. If the photographer were standing twice as far from the tree, it would appear half the size. The size of Orion would not change. By changing that distance, the tree could appear ten times larger than Orion or ten times smaller.

I do a lot of cropping to fit screen size for my desktop screen and have never run into that! So Whatever!

Not sure what you mean. The relative sizes have nothing to do with cropping. They depend only on the distance between the camera and the foreground (terrestrial) objects or landscape.

Which of these is more "real"? (The background tree is the same size in both.)
_
Scale2.jpg

orin stepanek wrote: ↑Mon Sep 30, 2019 9:58 pm

Chris Peterson wrote: ↑Mon Sep 30, 2019 9:33 pm
What is a "normal sized tree"? The only thing that determines the relative sizes of the tree and Orion is the distance of the camera from the tree. If the photographer were standing twice as far from the tree, it would appear half the size. The size of Orion would not change. By changing that distance, the tree could appear ten times larger than Orion or ten times smaller.

I do a lot of cropping to fit screen size for my desktop screen and have never run into that! So Whatever!

https://www.quora.com/What-are-the-smallest-and-lightest-bonsai-trees wrote:
What are the smallest and lightest bonsai trees?
Tom Kehoe, Curator of the James J. Smith Bonsai Collection.

---

<<In the US, we refer to the tiniest size bonsai as “mame” or bean-sized, but in Japan they may break it down even further to shito (fingertip) and keshitsubo (poppy-seed). These are an incredible challenge and require techniques that are specialized even within the specialized world of bonsai.

They have such a tiny living space that just keeping them properly watered and fertilized can be a challenge. There is very little margin of error. A single forgetful moment can spell doom. A single leaf may represent an entire branch. Delicate species with tiny leaves may be used to help create the tiny tees.

They are often created from hardwood cuttings from larger trees, in order to get a turn that has some taper to it. For some species, this may mean air-layering the donor tree. Transplanting them requires tiny versions of specialized bonsai tools, and many experts make or improvise their own.>>

orin stepanek wrote: ↑Mon Sep 30, 2019 9:58 pm

Chris Peterson wrote: ↑Mon Sep 30, 2019 9:33 pm
What is a "normal sized tree"? The only thing that determines the relative sizes of the tree and Orion is the distance of the camera from the tree. If the photographer were standing twice as far from the tree, it would appear half the size. The size of Orion would not change. By changing that distance, the tree could appear ten times larger than Orion or ten times smaller.

I do a lot of cropping to fit screen size for my desktop screen and have never run into that! So Whatever!

Chris Peterson wrote: ↑Mon Sep 30, 2019 9:33 pm
What is a "normal sized tree"? The only thing that determines the relative sizes of the tree and Orion is the distance of the camera from the tree. If the photographer were standing twice as far from the tree, it would appear half the size. The size of Orion would not change. By changing that distance, the tree could appear ten times larger than Orion or ten times smaller.

Chris Peterson wrote: ↑Mon Sep 30, 2019 9:33 pm
What is a "normal sized tree"? The only thing that determines the relative sizes of the tree and Orion is the distance of the camera from the tree. If the photographer were standing twice as far from the tree, it would appear half the size. The size of Orion would not change. By changing that distance, the tree could appear ten times larger than Orion or ten times smaller.

orin stepanek wrote: ↑Mon Sep 30, 2019 7:40 pm

Chris Peterson wrote: ↑Mon Sep 30, 2019 1:52 pm

orin stepanek wrote: ↑Mon Sep 30, 2019 11:56 am Beautiful; but I never seen Orion that big in the sky! Surely the photo was exaggerated! 8-)

No. The image is simply cropped so it fills the frame.

Don't mean to be negative; but that is exaggerating the picture! Also that doesn't explain the normal sized tree unless the tree was added later! JMHO :wink:

orin stepanek wrote: ↑Mon Sep 30, 2019 7:40 pm

Chris Peterson wrote: ↑Mon Sep 30, 2019 1:52 pm

orin stepanek wrote: ↑Mon Sep 30, 2019 11:56 am
Beautiful; but I never seen Orion that big in the sky! Surely the photo was exaggerated!

No. The image is simply cropped so it fills the frame.

Don't mean to be negative; but that is exaggerating the picture!

Also that doesn't explain the normal sized tree unless the tree was added later! JMHO

https://www.etymonline.com/search?q=crop wrote:
<<crop (n.) Old English cropp "head or top of a sprout or herb, any part of a medicinal plant except the root," also "bird's craw" (the common notion is "protuberance"), cognate with Old High German kropf, Old Norse kroppr.

Meaning "grain and other cultivated plants grown and harvested" is from early 14c. (in Anglo-Latin from early 13c.). Probably this sense development is via the verbal meaning "cut off the top of a plant" (c. 1200).

From the notion of "top" comes the sense "upper part of a whip," hence "handle of a whip" (1560s), hence "a kind of whip used by horsemen in the hunting field" (1857). "It is useful in opening gates, and differs from the common whip in the absence of a lash".>>

Chris Peterson wrote: ↑Mon Sep 30, 2019 1:52 pm

orin stepanek wrote: ↑Mon Sep 30, 2019 11:56 am Beautiful; but I never seen Orion that big in the sky! Surely the photo was exaggerated!

No. The image is simply cropped so it fills the frame.

Chris Peterson wrote: ↑Mon Sep 30, 2019 1:50 pm

starsurfer wrote: ↑Mon Sep 30, 2019 11:12 am
Can starlight induce photosynthesis?

In general, yes (although not enough to have any biological significance to a plant). The photosynthetic pathway is triggered whenever a photon is captured. That said, there are probably some plants that shut down a part of that pathway when light levels are low, preventing the creation of sugars. Think of it as a sort of plant analog to sleeping.

https://i.pinimg.com/736x/4b/5e/3b/4b5e3b3dc3d02b07dd344cd7d19ad68d.jpg wrote:

Photograph by Tim Laman, National Geographic

---

<<Cassiopea andromeda, the upside-down jellyfish, is named for one of Greek mythology’s treacherous queens. Cassiopeia was punished by Poseidon, who deemed that her constellation often appear upside-down in the sky. Her namesake jelly often lies on the seafloor with its mouth and arms facing the surface, which allows symbiotic algae to collect sunlight for photosynthesis and pass nutrients along to the jelly. Crabs sometimes carry these jellyfish on their backs to serve as a very effective protective shield.>>

https://en.wikipedia.org/wiki/Cassiopea wrote:
Certain species of Cassiopea have been observed to enter a sleep state, indicated by a decreased pulsation rate.

https://en.wikipedia.org/wiki/Sleep_in_non-human_animals#Invertebrates wrote:
<<Sleep as a phenomenon appears to have very old evolutionary roots. Unicellular organisms do not necessarily "sleep", although many of them have pronounced circadian rhythms. The jellyfish Cassiopea is the most primitive organism in which sleep-like states have been observed. The nematode C. elegans is another primitive organism that appears to require sleep. Here, a lethargus phase occurs in short periods preceding each moult, a fact which may indicate that sleep primitively is connected to developmental processes. Raizen et al.'s results furthermore suggest that sleep is necessary for changes in the neural system. The electrophysiological study of sleep in small invertebrates is complicated. Insects go through circadian rhythms of activity and passivity but some do not seem to have a homeostatic sleep need. Insects do not seem to exhibit REM sleep. However, fruit flies appear to sleep, and systematic disturbance of that state leads to cognitive disabilities. There are several methods of measuring cognitive functions in fruit flies. A common method is to let the flies choose whether they want to fly through a tunnel that leads to a light source, or through a dark tunnel. Normally, flies are attracted to light. But if sugar is placed in the end of the dark tunnel, and something the flies dislike is placed in the end of the light tunnel, the flies will eventually learn to fly towards darkness rather than light. Flies deprived of sleep require a longer time to learn this and also forget it more quickly. If an arthropod is experimentally kept awake longer than it is used to, then its coming rest period will be prolonged. In cockroaches that rest period is characterized by the antennae being folded down and by a decreased sensitivity to external stimuli. Sleep has been described in crayfish, too, characterized by passivity and increased thresholds for sensory stimuli as well as changes in the EEG pattern, markedly differing from the patterns found in crayfish when they are awake. In honeybees, it has been suggested they could be able to dream.>>

orin stepanek wrote: ↑Mon Sep 30, 2019 11:56 am Beautiful; but I never seen Orion that big in the sky! Surely the photo was exaggerated! 8-)

starsurfer wrote: ↑Mon Sep 30, 2019 11:12 am Can starlight induce photosynthesis?

Alnitak (ζ Orionis) is a triple star system at the eastern end of Orion's belt and is 1,260 light-years from the Earth. Alnitak B is a 4th-magnitude B-type star which orbits Alnitak A every 1,500 years. The primary (Alnitak A) is itself a close binary, comprising Alnitak Aa (a blue supergiant of spectral type O9.7 Ibe and an apparent magnitude of 2.0) and Alnitak Ab (a blue dwarf of spectral type O9V and an apparent magnitude of about 4). Alnitak Aa is estimated as being up to 28 times as massive as the Sun, and to have a diameter 20 times greater. It is the brightest star of class O in the night sky.

Alnilam (ε Orionis) is a supergiant, approximately 2,000 light-years away from Earth and magnitude 1.70. It is the 29th-brightest star in the sky and the fourth-brightest in Orion. It is 375,000 times more luminous than the Sun.[5] Its spectrum serves as one of the stable anchor points by which other stars are classified.

Mintaka (δ Orionis) is 1,200 light-years away and shines with magnitude 2.21. Mintaka is 90,000 times more luminous than the Sun. Mintaka is a double star. The two stars orbit around each other every 5.73 days.[6]/quote]